Yamaha Outboard Lower Unit

Replacing a Yamaha outboard lower unit typically costs between $800–$2,500, depending on the model, HP, and whether you choose a new, remanufactured, or used unit. Remanufactured lower units from Mariners Warehouse offer OEM-level performance at a significantly lower cost than a brand-new unit, with a warranty included for peace of mind.

Common signs of a failing lower unit include grinding or whining noises while shifting, milky or discolored gear oil (indicating water intrusion), difficulty shifting gears, vibration at speed, or visible fluid leaks near the propeller housing. If you notice any of these, it's best to have the unit inspected before it causes further damage to internal gears and bearings.

You can identify the correct lower unit by checking your outboard's model number, HP rating, shaft length, and gear ratio, or by matching the part number stamped on your existing lower unit. Our compatibility chart lets you cross-reference your engine's specs to find the exact remanufactured lower unit that fits your model.

A new lower unit comes directly from Yamaha at the highest price point. A used lower unit is a pulled unit with unknown internal wear. A remanufactured lower unit is fully disassembled, inspected, and rebuilt with new seals, bearings, and gears where needed — giving you reliability close to new at a fraction of the cost, which is why it's the most popular choice among boat owners.

Yamaha lower unit rebuild kits generally range from $150–$500 depending on the model and what's included (seals, bearings, gears, shims). If you're not confident rebuilding it yourself, a fully remanufactured lower unit is often a better value since it eliminates the labor and risk of missing a worn component.

Some Yamaha lower units are compatible across multiple model years and HP ranges within the same family (for example, certain F150/F200 series units share the same gearcase), but shaft length and gear ratio must always match. Check our compatibility table above or contact us with your engine's model number to confirm fitment before ordering.

With regular gear oil changes and proper care, a Yamaha lower unit can last 10–15 years or more. Saltwater use, infrequent maintenance, or hitting debris can shorten its lifespan significantly, which is why routine inspection is recommended at least once a season.

Mariners Warehouse specializes in remanufactured Yamaha lower units, each rebuilt to OEM specifications and tested before shipping. Browse our lower unit collection by model and HP to find the exact match for your outboard, backed by our warranty.

Yes — if your lower unit only needs specific components rather than a full replacement, we carry individual gearcase parts such as seals, bearings, water pumps, and shift components for most Yamaha outboard models.

Used lower units are sold as-is since their internal condition can't be fully verified without teardown. For guaranteed reliability, we recommend a remanufactured lower unit instead, which comes fully inspected, rebuilt, and covered under warranty.